Re: [PATCH 18/18] signed push: final protocol update

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 25, 2014, 17:59 UTC
Message-ID: <xmqqd2bomowm.fsf@gitster.dls.corp.google.com>
In-Reply-To: <CAJo=hJu_T7irRk=fBsJ+GQxbVQ9GgO2ytihxKm+bXSLsL+wQbg@mail.gmail.com>

Shawn Pearce <spearce@spearce.org> writes:

Show 12 quoted lines

> A stateless nonce could look like:
>
>   nonce = HMAC_SHA1( SHA1(site+path) + '.' + now, site_key )
>
> where site_key is a private key known to the server. It doesn't have
> to be per-repo.
>
> receive-pack would then be willing to accept any nonce whose timestamp
> is within a window, e.g. 10 minutes of the current time, and whose
> signature verifies in the HMAC. The 10 minute window is important to
> allow clients time to generate the object list, perform delta
> compression, and begin transmitting to the server.

Hmph, don't you send the "finally tell the other end" the sequence of "update this ref from old to new" and the packdata separately? I think we have a FLUSH in between, and the push certificate is given before the FLUSH, which you do not have to wait for 10 minutes.